A Differential Polarization-time Coding Scheme for Polarization-division-multiplexed Fiber-optic Communication Systems

• Main Author: Pan, Chunpo
• Other Authors: Kschischang, Frank R.
• Language: en_ca
• Published: 2010
• Subjects: optical; communications; fiber; polarization mode dispersion; MIMO; unitary group; differential; coding; 0544
• Online Access: http://hdl.handle.net/1807/25890

Polarization division multiplexing (PolDM) is a promising way to improve the spectral efficiency of fiber-optic communication systems. However, PolDM systems suffer greatly from polarization mode dispersion (PMD), especially in long-haul systems. PMD is time-varying and is intrinsically hard to compensate. Current PMD compensators are complicated and expensive to build, adding to the cost and complexity of practical PolDM systems. We propose a new differential polarization time coding scheme combined with controlled polarization rotation to increase the system tolerance to PMD. An encoding algorithm, a differential receiver design, and a decoding algorithm are described in detail. Controlled polarization rotation is achievable using conventional Mach-Zehnder interferometers that are used to modulate the signal. Simulation results show that significant improvement in PMD tolerance can be achieved with little added complexity. Given a certain transmission distance, our proposed system can also increase the achievable data rate compared to a PolDM differential quadrature phase shift keying system.